Greetings all,
I have come from the eskate community and I am now interested in building a cheap ebike. I was just going to get a crappy chinese 48v 1000w kit off ebay. What do you guys recommend for batteries. A 10s battery system is pretty standard for electric skateboards. What lipo battery packs do you recommend running for an ebike. I used these batteries for my skateboard https://hobbyking.com/en_us/zippy-fligh ... p-30c.html. What would be the cheapest way for me to build a battery setup with lipos?

Yes, Hobbyking LiPo will be the cheapest way to go. What kind of range are you chasing? I believe some high capacity cells are out there, like 8000 mAh, but most are around 5000. You would need to parallel a couple of packs and then put these in series. Search the forum for examples - Icecube does some sweet adapters.

Matt_54 wrote:Greetings all,
I have come from the eskate community and I am now interested in building a cheap ebike. I was just going to get a crappy chinese 48v 1000w kit off ebay. What do you guys recommend for batteries. A 10s battery system is pretty standard for electric skateboards. What lipo battery packs do you recommend running for an ebike. I used these batteries for my skateboard https://hobbyking.com/en_us/zippy-fligh ... p-30c.html. What would be the cheapest way for me to build a battery setup with lipos?

Just bought one of those kits myself just want a cheap reliable commuter, since i keep breaking bikes that are both commuter and for fun.
personally im dipping in to some spare 4s 5ah hardcase packs i have lying around, but if your buying new the multistar 16-20ah 6s packs are good value, and save you a lot of parallel connections. just get 2, put in series, and you have a 48v 20ah pack. would have done exactly that myself if i didn't have spares already. should be easy too to make up a series - parallel plug to charge on a conventional lipo charger too... you can find many such examples on ES already (though im guessing you may already know given your background).

Yeah those 6s 16000mah batteries were once priced very well now they're a little more pricy. Would anyone recommend this chinese made 48v 12ah pack? http://www.ebay.com/itm/132073702029?_t ... EBIDX%3AIT It costs about as much as buying lipos then connecting them in parallel and series several times, but it comes in a complete form. Would that work as an easy plug and play for a 48v 1000w hub kit?

Matt_54 wrote:Yeah those 6s 16000mah batteries were once priced very well now they're a little more pricy. Would anyone recommend this chinese made 48v 12ah pack? http://www.ebay.com/itm/132073702029?_t ... EBIDX%3AIT It costs about as much as buying lipos then connecting them in parallel and series several times, but it comes in a complete form. Would that work as an easy plug and play for a 48v 1000w hub kit?

The 6S 16000mah batteries frequently go on sale. I regularly see them in the ~$75.00 range.

Would you guys recomend the getting 2 250W 10A 6S Chargers found at: "https://hobbyking.com/en_us/turnigy-rea ... arger.html" to charge the two multistar 6s 16Ah packs? I also see the discharge rate on those packs is only 10c is that even suitable for ebiking?? That low of a discharge wouldn't be recommended for eskating. Now all I can do is wait for those packs to go on sale!

Matt_54 wrote:Would you guys recomend the getting 2 250W 10A 6S Chargers found at: "https://hobbyking.com/en_us/turnigy-rea ... arger.html" to charge the two multistar 6s 16Ah packs? I also see the discharge rate on those packs is only 10c is that even suitable for ebiking?? That low of a discharge wouldn't be recommended for eskating. Now all I can do is wait for those packs to go on sale!

The Multistars are good for up to 40 Amps constant depending on the capacity, plenty for your build.
The MS batt.s exchange C rate for compactness and lite weight.
Far and away, the best way to use Lipoly on an Ebike is to have a hard Low Voltage Cut-off. Most 36 V controllers have a LVC of 31 Volts, which leaves to cell Voltage too low @ 10S, but you can use 9S.
A 48 V controller has a 42 LVC, which leaves the cells @ 3.65 V/cell, perfect. For this, and other reasons, I recommend 48V systems.

Also, some sine-wave controller/displays have a hard time reading the odd Voltage of LiPoly.

Use the biggest bricks you can fit in your space that meets your capacity requirements.
If you can stay @ 2P, you can forgo the BMS and ck. and balance w/ Battery Medics.
This pack is 12S/2P, 20 Ah capacity. Four MS 6S/10Ah bricks wired 2S/2P;

100_0064.JPG (73.17 KiB) Viewed 580 times

If I don't go all the way down to LVC, 95% of the time, I don't have to balance, I just ck. them.
You understand that, if you are not going out to ride, you will have to leave the pack @ 3.90V/cell "storage Voltage" to extend the service life of the batt.s. I top off right before I go out and w/ my HGL, it only takes 20 min.s to charge to 4.15V/cell. But I have so much capacity, that I usually just charge to 4.05V, which only takes 10 min.s.

Last edited by motomech on May 10, 2017 8:16 pm, edited 5 times in total.

You are correct to "bulk charge". Once the pack is configured, it's best to not dis-connect the leads that "join "the bricks. Lipo in a sense has a memory and leaving the bricks together helps the cells to "settle-in", which in turn, helps the cells to remain balanced. This will also help prevent mistakes.

Some Battery Medics work better than others. I have had the best luck w/ these;

Matt_54 wrote:Using BMS why do you need all those battery medics the BMS will control voltage? Then you could just check the cells to make sure they're balanced?

I don't use any BMS and don't "break" my packs. The controller takes care of the LVC and as I bulk charge, I ck them w/ a Battery Medic.
I have 4 BM's because;
If I go down the LVC, the cells start to stray and I might have to balance. The fastest way is 4 BM's, one for each brick.
Or,
More likely, let's say I have top charged and for some reason, don't go out for a ride. Then I need to bring the pack back down to storage Voltage.

you use the Meanwell HGL 320-54A? How exactly do you set the charger up? Are LED power supplies easily used for charging lipos? You only use the dc converter going into the BM and that's all you need? Seems pretty straight forward. What's your range with 20AH? It looks to me 16AH will be well more than enough for my use. Also does that power supply ever have any overheating issues with its very rugged design to be weather proof it seems it would overheat easily, is there something you do to avoid that? I have never charged this way with battery medics What prevents the cells from overcharging? is the power supply set to cut off once it reaches a certain voltage? Or do the battery medics discharge not allowing the cells to keep charging counteracting the power supply??

Yeah, after the expensive Satiator from Grin, the HGL is the best LiPoly bulk charger there is. I have 2, a 54A and a 48A.
Using them is too simple, they have two pots that are weather sealed. You can see the screwdriver in my pic.
The finish Voltage is adjustable + or- 5V. I set to 48V for storage and 50V for top charge. I leave the Current @ max, about 7.5 Amps.
It's fool-proof to start, you can plug it in(120AC)and then connect it to the batt. or visa-versa, it doesn't care.
It's dead silent and barely gets warm. It doesn't waste time cycling on/off to read the cells like a balance charger, so it's fast. It's CV/CC, so as it' gets close to finish charge, the current atenuates, eventualy to just a trickle. At the finish, you can hear a soft switching inside and it's safe to leave it connected, so you don't have to stand there and watch it(But I still stay close). It's fully potted, so it can be carried on the bike, but it is heavy. It's important to get the model w/ the "A" suffix, as this is the adj. version.
I have had a bunch of balance chargers, good ones too, Thunder 1220, Hyperion 1420, etc. and they have all died after a year or two. The HGL is made to run 24/7 and bullet-proof. The best money I have spent on my Ebike.

All the Battery Medics do is "bleed"off Voltage. They have two modes, balance or set voltage. They are sloooow, to go from 4.15V to 3.90V could take a couple of hours. But they are safe to leave on and forget. I sometimes discharge overnite. When they reach the set Voltage, they beep softly.
But the point is, if your pack is big enough and is never discharged low, balancing become a thing of the past. Like I said, I ck. them every time and they are good to go 95% of the time.

I have all the components for my ebike I just have to assemble. First off what gauge wire do you use? I plan on wiring a watt meter, lights and other accessories. It seems that 10awg will be more than enough.

10 awg wire is heavy, a little too thick to use w/ 4 mm bullet connectors and not needed. For building my pack, I use 14 Awg, which matches the 4 mm bullet Y connectors (Ebay) I use to parallel the bricks and the leads on the Watt meter. Sometimes I use 12 awg for the final run from the pack to the controller, but I doubt it's needed for 12S to 14S.
Speaking of the Watt meter, I have one, but I only use it for testing the controller's output. Since it needs to be placed in series in a spot where it's visible, that usually means extra run of large gauge wires that are not stealthy. And it also needs to have a switch or the LED screen will drain the batt., a PITA. The only info I deem necessary concerns Volts, a meter as a "fuel" gauge and maybe a low Voltage alarm. A LCD Voltmeter (no drain)only needs thin gauge wires that are easy to hide. Everything else is just entertainment.

Also what storage voltage do you set your batteries to? Reading over the forum I believe you have your batteries set at 3.90 v but storage voltage is usually 3.70-3.80.

3.70V to 3.80V/cell takes too long to top charge when you are waiting to ride. 3.90 V is fine for MultiStar and if I'm only going on a short ride, I go at that Voltage. Longer rides, I go to 4.10V, which doesn't take long.

When you are riding how low do you let your voltage go around 3.60? Also I have hobby king battery medics and personally they seem useless. After discharging for a day they have not performed at all they’ve only unbalanced. I just wanted to test them out and attempted to balance the cells to 3.75 when most of the cells were at 3.76 to get all cells perfectly in balance. After checking the BM the next day the cells are at 3.74 3.75 and 3.76. The BM is still balancing away what battery medics do you use?

I warned you about which Battery Medics in an above post. Here is another post I just made;
"
Unfortunately, the Original Battery Medic has been cloned and the clones are junk. The Black ones are especially bad as they over-heat and the screen goes black. HK should not be selling those as they are a rip off.
There are two Blue ones that work OK, but one is better than the other.
The best ones have the higher-discharge light-bulb arary for a faster discharge, like this one;https://www.amazon.com/Targethobby-Disc ... discharger
The light bulbs are not necessary to use, but this BM allows setting the Values by .01 V, ie; 3.91V, 3.92V, 3.93V, etc.
The other Blue ones only allow setting the values by .05V, ie; 3.90V, 3.95V, 4.00V, etc."
Also the original link;https://www.aliexpress.com/item/150W-3- ... 17404.html
I don't know what you re doing with the Battery Medics, but they are dead simple and work every time for me. The only prob. I have ever had w/ them is the over-heating prob. w/ the black ones that I out-lined above.

Also do you just use a voltage meter on your charger or do you use a watt meter so you can see the amps too.

Yes, I use both. The Watts start to fall off when nearing top charge and after a while, you will know when to adj. the top charge value by the Current reading. You can use that 10 awg wire you don't need to make long leads that reach the pack on the bike. Trim the core to fit the 4 mm bullets.